That prompted a disconsolate shake of the head from Sherwood, who was watching from high in the stands after several weeks of manic antics on the touchline.

But to their credit, Sherwood's players, criticised by their manager for lacking spirit after a recent thrashing at Chelsea, refused to surrender and staged a strong comeback to avoid a fourth successive defeat.

Chadli started the revival when he equalised with a powerful low shot from the edge of the area in the 78th minute.

And the Belgian winger struck again one minute later, swivelling to sweep home Harry Kane's knock-down.

Benfica were shell-shocked and the visitors poured forward in search of the third goal which would have forced extra-time.

They appealed in vain for a penalty when Kane was bundled over by Miralem Sulejmani and moments later it took a fine save from Jan Oblak to deny Gylfi Sigurdsson's header.

As Tottenham threw bodies forward they were caught on the break and Sandro chopped down Lima, who picked himself up to stroke home the penalty and finally settle the tie.